For each group of three forces below, determine whether the forces in each pair are pulling at right angles to each other. 13 lb, 35 lb, resultant force 30 lb, yes; 20 lb, 15 lb, resultant force 25 lb, yes 13 lb, 35 lb, resultant force 30 lb, no; 20 lb, 15 lb, resultant force 25 lb, no 13 lb, 35 lb, resultant force 30 lb, no; 20 lb, 15 lb, resultant force 25 lb, yes 13 lb, 35 lb, resultant force 30 lb, yes; 20 lb, 15 lb, resultant force 25 lb, no